Abstract: By using SnCl₂·2H₂O and tetraethyl orthosilicate as raw materials, polystyrene colloidal crystal
with diameter of 585nm as template, three-dimensional ordered macroporous (3DOM) SnO₂ and SnO₂/SiO₂ were successfully synthesized.
SEM observation shows that 3DOM SnO_2 has a pore size of 453～500nm, and 3DOM SnO₂/SiO₂ has a pore size of 500nm. And such macropores
connect with each other by small windows. Compared with the polystyrene colloidal crystal used, the 3DOM materials show shrinkage to some extent
in pore size. The study indicates that it is difficult to obtain ordered pore structure when SnCl₂ is used as precursor directly. But addition of
tetraethyl orthosilicate or conversion of SnCl₂ solution to oxide sol favors the formation of the highly ordered macroporous structure. XRD
measurement indicates that the walls of the 3DOM materials are made of SnO₂ nanoparticles with particle sizes around 17nm.

Key words: colloidal crystal, polystyrene, three-dimensional ordered macroporous, SnO₂